Medium [CVE-2026-18967] Keycloak-services: keycloak-services: saml onetimeuse assertion replay in idp-initiated broker flow
This medium-severity Red Hat Linux advisory covers CVE-2026-18967 affecting Red Hat Build of Keycloak, Red Hat JBoss Enterprise Application Platform Expansion Pack.
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Summary
A flaw was found in the SAML broker component of Keycloak, an identity and access management solution. When configured as a SAML broker using the IdP-Initiated flow, Keycloak fails to enforce the OneTimeUse condition in SAML assertions.
This allows an attacker who captures a valid, unused assertion to replay it multiple times. Successful exploitation could allow an attacker to hijack a user's session and gain unauthorized access to the system as that user.
Affected products named by the advisory: Red Hat Build of Keycloak; Red Hat JBoss Enterprise Application Platform Expansion Pack.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 2 hours ago·verify at source
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